1. Field
The present invention relates to a vane system equipped with a guiding mechanism, for a centrifugal compressor.
In particular, the invention relates to a vane system for a centrifugal compressor with a cylindrical box, equipped with a guiding system.
2. Brief Description of Related Developments
Among the numerous applications of centrifugal compressors, those which require the presence of adjustable vanes at the inlet of the compressor, also known with the acronym of IGV (Inlet Guide Vanes) are familiar.
Adjustable vanes (IGV) can be regulated/rotated in order to position them at a suitable angle with respect to the direction of the inlet fluid to be compressed.
The use of centrifugal compressors in industrial production and synthesis processes, is well known.
Among the various applications, those operating on two different streams inside the same compressor, such as, for example, in the synthesis of ammonia and methanol, are also known.
In the latter plants, a two-phase compressor is used, wherein the first phase consists of reaction reintegration and the second of reactor recycling.
The suction pressure and composition are different in the two streams.
The flexibility control of the plant is highly conditioned as, in this configuration, the reintegration and recycling phase are connected and there is no way of modifying the pressure ratio between the two phases, unless an anti-pumping system for both phases is installed.
In the plants according to the known art, the compressor for the synthesis of methanol, as in general, all compressors destined for synthesis process plants, are provided, in some cases, with a suction chamber equipped with adjustable vanes (IGV), whereas, in other cases, the performance control is effected by the regulation valve situated in the suction duct of the recycling phase.
The latter solution is considered obsolete and has various disadvantages, in particular with respect to efficiency and control.